A successful immunofluorescence technic for detection of estrogen receptor in human breast cancer has been developed. The method is based on the use of an estradiol polymer bound to the specific receptor, on frozen sections of tumor. The polymer acts as a large antigen target for subsequent binding of antibody and labeled conjugate. We propose to synthesize water soluble polymers of progesterone, testosterone and glucocorticoid hormones suitable for use in immunofluorescence studies designed to detect specific receptor for these steroids in human mammary carcinoma. Results by immunofluorescence will be compared to those of conventional biochemical assay and correlated with clinical response to therapeutic hormonal manipulations.